Date : Tue, 06 Apr 2010 17:22:35 +0100
From : philpem@... (Philip Pemberton)
Subject: "open" beeb bits...
Jules Richardson wrote:
> The TUBE ULA's obviously one - same with the video ULA.
The TUBE ULA could probably be reimplemented in a CPLD if you were that
way inclined. You could most likely stuff a coprocessor core (say, a
Microblaze or a Picoblaze) and the ULA bits into a modern entry-level FPGA.
> Maybe the 1770 and
> 8271, too (although perhaps re-implementations of those already
exist, given that they weren't exclusive to Acorn?).
The Suska (Atari ST in an FPGA) project has already done a Verilog (or
maybe VHDL) implementation of a 1772. Not that much difference between
that and a 1770 (just step rates IIRC).
> [1] personally I've no problem with John designing a new TUBE ULA and
not making it generally available - but I do think that the beeb
community *needs* an "open" ULA design within the next few years (I've
certainly got more beeb things that use the ULAs than I have functioning
ULA chips)
My process for hardware licensing is generally:
- I release the HDL code and firmware under the GPL (to stop "certain
folk" from making small changes and claiming the whole thing as theirs)
- If I'm selling PCBs, kits, etc. then the PCB files stay with me.
You're welcome to design your own PCB, but I'd prefer it if you didn't
sell them on (I don't want a million clones in the marketplace and a
similar number of people whining about hardware bugs in the clones that
aren't present in my "reference design").
- If I'm not selling PCBs/kits/etc.. it's basically fair game, though
I'd appreciate some acknowledgement. "DSGN: P. PEMBERTON, PCB: J.
BLOGGS" on the PCB is plenty. Engaging in the ritual Sharing Of The
Takings is encouraged, but not required :)
- If it gets to the point where I really don't want to bother selling
PCBs and kits of a given product any more... I'll probably stick the
Gerbers and EAGLE CAD files up on a website somewhere for free download.
--
Phil.
philpem@...
http://www.philpem.me.uk/